<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>判断成绩级别</title>
</head>
<body>
    <script>
        var score = prompt('请输入你要查询的成绩：');
        if (score >= 90) {
            alert('您的成绩级别是A哦！');
        } else if (score >= 80) {
            alert('您的成绩级别是B哦！');
        } else if (score >= 70) {
            alert('您的成绩级别是C哦！');
        } else if (score >= 60) {
            alert('您的成绩级别是D哦！');
        } else {
            alert('你不及格哦！请加倍努力把！');
        }
    </script>
</body>
</html>